I am always searching for something unique to give to family and friends for Christmas. One year, it was maple syrup aged in bourbon barrels, and another year was a sample set of different mustards from the National Mustard Museum. This year I decided to order genetic testing kits. What a great gift to give if you are a science nerd like me. You can also learn more about your family and friends if they share the results.

These genetic testing kits are sophisticated and produce an extensive genetic analysis. Multiple companies can do the testing, and they offer information on your ancestry, health and other things.

Typically, you provide a saliva sample, which they can use to get your DNA. Ancestry.com uses something called microarray autosomal testing to get gene information from 700,000 locations on the genome. You receive your results by logging into a website with an ID and password. And voila – there is your DNA information.

All the companies say they take privacy seriously, with policies to secure your DNA sample, any personal data provided and your DNA data. At least one company allows you to download your data and delete the results from its records.

The testing provides information about your ethnicity for more than 300 global regions. Depending on which company you use, you can also match your DNA information to other people in their database to find family. Ancestry.com has about 7 million people in its database, and billions of historical records. 23andMe has around a million people in its database.

In addition to your ancestry information, you can learn about your genetic risk for disease. This could be important if hereditary diseases like Huntington’s run in your family. You may also find out if you are susceptible to certain cancers, such as breast or colon cancer. If you know your risk in advance, you could be ready to deal with symptoms or catch the early onset of these conditions when they could be more treatable. But this information could also be distressing. Do you really want to know that you might (or might not) develop a devastating disease later in life?

Information about your family could be harmful also. After getting their DNA tested, some discover that their parents are not who they thought or find previously unknown siblings. Revelations like this can bring chaos and even divorce to a family.

There are also reports of artificial insemination switching revealed by the genetic tests. 23andMe testing recently revealed that a child conceived through artificial insemination was not the father’s – he and the daughter did not share any genetic markers. It turned out that the father’s sperm were replaced with those of a receptionist at the fertility clinic. In another case, a fertility doctor, instead of anonymous donors, was found to have fathered more than 15 children.

There are a lot of positives from genetic testing — learning about your heritage and assessing your future health. As with most things though, it comes with a risk.

Medical Discovery News is hosted by professors Norbert Herzog at Quinnipiac University, and David Niesel of the University of Texas Medical Branch. Learn more at medicaldiscoverynews.com.